Communication apparatus and method for reconfiguring communication apparatus

ABSTRACT

Digital signal processing section  103  has reconfigurable device  131 , and reconfigurable device  131  configures decoding section  133  and coding section  134  by programming data. Decoding section  133  acquires synchronization from a signal output from reception section  121 , and demodulates and decodes the signal. CPU  105  downloads programming data of another radio communication system to store in storage section  106  via general bus  104 . Further, CPU  105  reads out the stored programming data, and reconfigures reconfigurable device  131 . Storage section  106  stores the programming data.

TECHNICAL FIELD

The present invention relates to a communication apparatus andcommunication apparatus reconfiguration method, and more particularly,to a communication apparatus and communication apparatus reconfigurationmethod suitable for use in a hand over system for switching between aplurality of radio communication systems.

BACKGROUND ART

Currently, various radio communication systems exist such as 2ndgeneration radio communication systems such as PDC and GSM, 3rdgeneration radio communication systems such as W-CDMA, and PHS andwireless LAN. As a technique for supporting a plurality of radiocommunication systems using a single radio apparatus, software definedradio exists that varies between functions by updating of software(programming data).

When switching between radio communication systems (which generallymeans handover between radio communication systems or the case ofupdating programming data, but it is herein assumed that handoverincludes the case of only updating programming data), a conventionalsoftware defined radio apparatus downloads software to support acommunication system of a handover destination switching from acommunication system used in current communications of a communicationapparatus, and then, reconfigures a communication apparatus thatsupports a radio communication system of the handover destination usingthe downloaded data.

With respect to switching of radio communication systems, there is amethod for implementing the switching by reprogramming (reconfiguring) areconfigurable device (for example, see Japanese Laid-Open PatentPublication H11-220413). Further, it is considered providing a downloaddedicated channel to implement fast download (for example, see JapaneseLaid-Open Patent Publication 2000-324043).

Currently, in a mobile communication terminal, it is demanded to switchfrom a communication system of current communications to anothercommunication system at high speed, and concurrently, it is desired toimprove the user capacity of the entire system. From these viewpoints,in the constitution as disclosed in Patent Document 1, a call issuspended or disconnected during download, and it is not possible toperform fast handover between radio communication systems. Further, asdisclosed in Patent Document 2, when a download dedicated channel isprovided to download programming data, there are possibilities thatspectral efficiency deteriorates and the user capacity of the entiresystem decreases.

When data of a radio communication system with a large amount(hereinafter, referred to as “large-scale”) of programming data isdownloaded during communication in a narrowband radio communicationsystem with low transmission rates, retransmission is apt to occur andit takes enormous time to complete the download. In particular,retransmission occurs remarkably in poor radio signal propagationcircumstances.

Further, when individual mobile communication terminals are operated toperform fast download in a wideband radio communication system with hightransmission rates, there arise problems that the spectral efficiencydeteriorates and the user capacity of the entire system decreases.

Furthermore, when a reconfigurable device such as a PLD (ProgrammableLogic Device) or FPGA (Field Programmable Gate Array) is used in themobile radio baseband signal processing, it is possible to support anyoperation such as, for example, FFT (Fast Fourier Transform),correlator, and FEC (Forward Error Correction), flexibility is thushigh, and development time is shortened. However, the circuit scale andpower consumption tends to increase in PLD and FPGA.

Meanwhile, when custom ASIC is used in the mobile radio baseband signalprocessing, it is possible to suppress the circuit scale and powerconsumption because of dedicated circuitry, but flexibility is lowbecause application is limited to, for example, FFT when FFT is used.Further, its development time is long.

As described above, in conventional apparatuses, when a communicationapparatus downloads programming data of a radio communication system andswitches details of the system to the downloaded programming data, thereexist such problems that an amount of programming data is large,download time is long, and it takes much time to switch between systems.

DISCLOSURE OF INVENTION

It is an object of the present invention to provide a communicationapparatus and communication apparatus reconfiguration method forreducing the time required for download without decreasing the usercapacity of the entire system, and as a result, switching betweencommunication systems for a short time.

The object is achieved by only reconfiguring a portion different among aplurality of radio communication systems, thereby decreasing an amountof data to reconfigure among the programming data of a target radiocommunication system, reducing the time required for download, andswitching between communication systems for a short time in a softwareradio apparatus that varies the function by rewrite of software forperforming signal processing.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating a configuration of acommunication apparatus according to Embodiment 1 of the presentinvention;

FIG. 2 is a block diagram illustrating a configuration of areconfigurable device of the communication apparatus of the aboveEmbodiment;

FIG. 3 is a block diagram illustrating a configuration of thereconfigurable device of the communication apparatus of the aboveEmbodiment;

FIG. 4 is a block diagram illustrating a configuration of thereconfigurable device of the communication apparatus of the aboveEmbodiment;

FIG. 5 is a block diagram illustrating a configuration of thereconfigurable device of the communication apparatus of the aboveEmbodiment;

FIG. 6 is a diagram illustrating an internal configuration of an FFTsection of the above Embodiment;

FIG. 7 is a diagram illustrating an example of an internal configurationof the FFT section in 4-point FFT;

FIG. 8 is a diagram illustrating an example of an internal configurationof the FFT section in 8-point FFT;

FIG. 9 is a block diagram of a correlator in the case of QPSK as anexample;

FIG. 10 is a diagram illustrating an internal configuration of acompensation section of the communication apparatus of the aboveEmbodiment;

FIG. 11 is a diagram illustrating an internal configuration of an FECsection of the communication apparatus of the above Embodiment;

FIG. 12 is a flow diagram illustrating an example of the operation whenretransmission is requested in the communication apparatus of the aboveEmbodiment;

FIG. 13 is a flow diagram illustrating an example of the operation whenretransmission is not requested in the communication apparatus of theabove Embodiment;

FIG. 14 is a block diagram common to a CRC processing unit and adescramble processor;

FIG. 15 is a block diagram common to a CRC processing unit and adescramble processor;

FIG. 16 is a block diagram common to a CRC processing unit and adescramble processor;

FIG. 17 is a block diagram common to a CRC processing unit and adescramble processor;

FIG. 18 is a block diagram illustrating a configuration of acommunication apparatus according to Embodiment 2 of the presentinvention;

FIG. 19 is a diagram illustrating an example of details stored in astorage device of the communication apparatus of the Embodiment;

FIG. 20 is a block diagram illustrating a configuration of a storagesection of the communication apparatus of the Embodiment;

FIG. 21 is a block diagram illustrating a configuration of aradio-section communication section of the communication apparatus ofthe Embodiment;

FIG. 22 is a block diagram illustrating a configuration of acommunication apparatus according to Embodiment 3 of the presentinvention;

FIG. 23 is a diagram illustrating a configuration of anattaching/detaching detection section of the communication apparatus ofthe Embodiment;

FIG. 24 is a diagram illustrating a configuration of theattaching/detaching detection section of the communication apparatus ofthe Embodiment;

FIG. 25 is a block diagram illustrating a configuration of acommunication apparatus according to Embodiment 4 of the presentinvention;

FIG. 26 is a view showing an example of the appearance of thecommunication apparatus of the Embodiment;

FIG. 27 is a block diagram illustrating a configuration of thecommunication apparatus of the Embodiment; and

FIG. 28 is a block diagram illustrating a configuration of anapplication section of the communication apparatus of the Embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

It is a gist of the present invention only reconfiguring a portiondifferent among a plurality of radio communication systems, therebydecreasing an amount of data to reconfigure among the programming dataof a target radio communication system, reducing the time required fordownload, and switching between communication systems for a short timein a software radio apparatus that varies the function by rewrite ofsoftware for performing signal processing.

Embodiments of the present invention will specifically be describedbelow with reference to accompanying drawings.

Embodiment 1

FIG. 1 is a block diagram illustrating a configuration of acommunication apparatus according to Embodiment 1 of the presentinvention. Communication apparatus 100 is mainly comprised of antennasection 101, radio section 102, digital signal processing section 103,general bus 104, CPU 105, storage section 106 and interface 107. Radiosection 102 is mainly comprised of reception section 121 andtransmission section 122. Digital signal processing section 103 hasreconfigurable device 131, and reconfigurable device 131 is connected togeneral bus 104 via CPU bus 132.

In FIG. 1, radio section 102 has reception section 121 and transmissionsection 122, and performs predetermined radio processing on a receptionsignal and transmission signal.

Reception section 121 receives a signal transmitted from a communicatingparty station not shown via antenna section 101, performs predeterminedradio reception processing (downconverting, A/D conversion, etc.) on thereceived signal (reception signal), and outputs the signal subjected tothe radio reception processing to digital signal processing section 103.

Digital signal processing section 103 has reconfigurable device 131, anddecoding section 133 and coding section 134 are configured byprogramming data in reconfigurable device 131.

Decoding section 133 acquires synchronization from a signal output fromreception section 121, performs demodulation and decoding on the signal,and outputs the decoded signal to CPU 105 via CPU bus 132 and generalbus 104.

CPU 105 functions as control means, and outputs a signal output fromdecoding section 133 to the outside, or outputs transmission data tocoding section 134 in digital signal processing section 103 describedlater. Further, CPU 105 downloads programming data of another radiocommunication system to perform handover for switching to the anothercommunication system during communications in some radio communicationsystem, and stores the data in storage section 106 via general bus 104.Furthermore, CPU 105 reads out the stored programming data toreconfigure reconfigurable device 131. Reconfiguration will specificallybe described later.

Coding section 134 encodes and modulates the transmission data outputfrom CPU 105, and outputs the modulated signal to transmission section122 in radio section 102. Transmission section 122 performspredetermined transmission processing (upconverting, D/A conversion,etc.) on the signal output from coding section 134, and transmits thesignal to a communicating party station not shown via antenna section101.

Storage section 106 stores the programming data. Interface 107inputs/outputs data to/from communication apparatus 100 from/to theoutside.

Radio communications are carried out in the aforementionedconfiguration. An example will be described below where digital signalprocessing section 103 is provided with reconfigurablility in a categoryof the baseband signal processing in mobile radio communications, andserves as a reconfigurable device specific to mobile radiocommunications, thereby eliminating the redundant flexibility andreducing the circuit scale of the digital signal processing section andprogramming data.

In the communication apparatus of the present invention, processingunits are provided originally that are elements for common use in aplurality of radio communication systems, only set are connectioninformation of connection between the internal processing units andcontrol information, a reconfigurable device is mounted that serves thefunction of performing desired-system baseband signal processing, and itis thereby possible to decrease an amount of data to reconfigure, reducethe time required for download, and switch between communication systemsfor a short time.

For example, in the communication apparatus of the present invention,some function (for example, FFT) shared by different radio communicationsystems to use is not mounted for each of the radio communicationsystems, and various processing units to implement FFT are mountedoriginally.

Then, the communication apparatus of the present invention obtains theinformation (control information) to control processing units andinformation (connection information) to connect the processing units byprogramming from the outside, is thereby capable of being provided withFFT corresponding to a plurality of radio communication systems, thusdesigned to have a circuit scale as small as possible and programmingdata as little as possible, and reduces an amount of data required forreconfiguration. In addition, specific contents of the connectioninformation and control information will be described later.

In this Embodiment, decoding section 133 will be described that isgenerally predominant in circuit scale among baseband signal processing.FIG. 2 is a block diagram illustrating a configuration of areconfigurable device of the communication apparatus according to thisEmbodiment. Reconfigurable device 131 in FIG. 2 is mainly comprised ofsynchronization section 201, second FFT section 202, second correlator203, ARQ processing section 204, compensation section 205, and FECsection 206.

Synchronization section 210 is mainly comprised of first FFT section211, first correlator 212, first storage section 213, and decisionsection 214. ARQ processing section 204 has second storage section 241.

In FIG. 2, based on a signal output from reception section 121,synchronization section 201 acquires and tracks synchronization of aradio communication system, searches for another radio communicationsystem as a destination of handover, and assigns a finger whennecessary.

When an OFDM (Orthogonal Frequency Division Multiplexing) system is usedas a modulation system, first FFT section 211 performs fast FourierTransform (hereinafter, referred to as FFT) on a reception signal, andstores FFT results in first storage section 213. Decision section 214performs comparison operation on the data stored in first storagesection 213 to search for a synchronization symbol that is knowninformation, acquires symbol synchronization, and outputs thesynchronization timing information to second FFT section 202.

Meanwhile, when a CDM (Code Division Multiplex) system is used as amodulation system, first correlator 212 performs correlation operationof a reception signal with a known signal sequence, and storescorrelation results in first storage section 213. Decision section 214searches for a greatest value and maximum value of data stored in firststorage section 213, acquires frame synchronization and spreading codenumber, and outputs the synchronization timing information and spreadingcode number to second correlator 203.

In particular, under multi-path propagation circumstances, a number ofmaximum values appear in stored correlation results (delay profile) andare called fingers, and there is a case of providing timing informationof each of the fingers also to second correlator 203.

Further, in the case of a system where OFDM and CDM are combined,synchronization is acquired in combining both systems.

For example, first FFT section 211 executes FFT, and stores FFT resultsin first storage section 213, decision section 214 acquires symbolsynchronization and outputs the synchronization timing information tosecond FFT section 202, and first correlator 212 also receives thestored data, performs correlation operation with a known signalsequence, and stores correlation results in first storage section 213.

Decision section 214 searches the stored data for a greatest value andmaximum value, acquires frame synchronization and spreading code number,and outputs the synchronization timing information and spreading codenumber to second correlator 203.

In addition, even synchronization is acquired once, in particular, inthe communication apparatus, or when a base station is moving, sinceradio signal propagation environments vary every instant andsynchronization is lost, it is necessary to track synchronization byperforming the procedures of synchronization acquisition at regular timeintervals, or the like.

Further, there is a case of acquiring synchronization of a handoverdestination while keeping current communications.

Based on the synchronization timing information output fromsynchronization section 201, second FFT section 202 performs FFToperation of a reception channel signal output from reception section121.

According to the synchronization timing information and spreading codenumber output from synchronization section 201, second correlator 203performs correlation operation of a reception channel signal output fromreception section 121 or second FFT section 202. Whether to receive thesignal from reception section 121 or second FFT section 202 is set asconnection information in reconfiguration.

Compensation section 205 calculates a phase rotation amount and anamplitude distortion value of a signal input from first correlator 212,second correlator 203, second FFT section 202 or ARQ processing section204 using a known signal (pilot signal), and performs complexmultiplication on the input signal using the calculated phase rotationamount and amplitude distortion value to make a phase correction andamplitude correction. Whether to receive the signal to process fromfirst correlator 212, second correlator 203, second FFT section 202 orARQ section 204 is set as connection information in reconfiguration.

Further, at the time of M-ary modulation with an M-ary number of 2^(n)(n is an integer of three or more) such as 16 QAM and 64 QAM, conversionto n items of data is also performed on complex symbol data subjected tothe phase correction and amplitude correction, for example, using alookup table. In addition, a value of n is set as control information inreconfiguration.

FFT section 206 performs error correcting processing such as Viterbidecoding and Turbo decoding on the data input from compensation section205 or ARQ section 204. FEC section 206 outputs an operation result tobit operation section 207.

According to circumstances, FEC section 206 receives an operation resultof bit operation section 207, and determines whether to perform FECprocessing again. Further, when determining that an error is notcorrected as a result of the FEC processing, the section 206 instructsARQ processing section 204 to hold the reception data. According tocircumstances, FEC section 206 outputs data to hold to ARQ processingsection 204.

Information set in reconfiguration includes the type of FEC such asViterbi decoding or Turbo decoding as control information, whether toreceive the signal from compensation section 205 or ARQ processingsection 204 as connection information, whether or not to receive theoperation result from bit operation section 207 as connectioninformation, and further, as control information, other information suchas a value of constraint length, generator polynomial, an input datalength and output data length.

ARQ processing section 204 stores in second storage section 241 the datainput from second correlator 203 or FEC section 206, and determineswhether or not to hold the stored data according to an instruction fromFEC section 206. When holding the data, ARQ section 204 outputs the datatogether with data to receive in a next frame to compensation section205 or FEC section 206.

Whether to receive the data from second correlator 203 or FEC section206 and whether to output the data to compensation section 205 or FECsection 206 is set as control information in reconfiguration.

Bit operation section 207 performs error detecting processing by CRCoperation and descrambling by descrambling processing on a bit sequenceinput from FEC section 206, or subjects a bit sequence input form CPUbus 132 to bit operation processing such as generation of parity bit byCRC operation, scrambling processing for scrambling data, and errorcorrecting code processing such as convolutional code and Turbo code.The details of the operation are set as connection information in bitoperation section 207 in reconfiguration.

With reference to FIGS. 3, 4 and 5, a case will be described below ofreconfiguring the digital signal processing section with theaforementioned configuration according to a radio communication system.FIGS. 3, 4 and 5 are block diagrams illustrating a configuration of thereconfigurable device of the communication apparatus of this Embodiment.FIG. 3 illustrates the digital signal processing section configured inthe first radio communication system. In the figure, the section isreconfigured using function blocks shown by boldface. With respect towiring shown by dotted lines, function blocks are not connected.Accordingly, all the functions are used in FIG. 3.

FIG. 4 illustrates the digital signal processing section configured inthe second radio communication system. In the figure, the section isreconfigured using devices shown by boldface. Accordingly, in FIG. 4,since first correlator 212, second correlator 203 and ARQ processingsection 204 are not used, the connection between the sections iscanceled and clock and power supply to the sections is halted.

FIG. 5 illustrates the digital signal processing section configured inthe third radio communication system. In the figure, the section isreconfigured using devices shown by bold face. Accordingly, in FIG. 5,since first FFT section 211 and second FFT section 202 are not used, theconnection between the sections is canceled and clock and power supplyto the sections is halted.

Thus, according to the communication apparatus of this Embodiment, onlyfunction blocks required for each radio communication system are used,connection between unused function blocks is canceled, and clock andpower supply to the blocks is halted. It is thereby possible to reducepower consumption.

Herein is described each function block shared by different radiocommunication systems to use. For example, by comparing FIG. 3 with FIG.4, it is understood that first FFT section 211 and second FFT section202 are used in both figures. However, specifications of the number ofsamples are different even in the same FFT section. Therefore, differentportions in an internal configuration of FFT are only reconfigured. FIG.6 is a diagram illustrating an internal configuration of the FFT sectionof this Embodiment.

First FFT section 211 and second FFT section 202 have a plurality ofbutterfly processing units as shown in FIG. 6. For example, using as abasic element the butterfly processing unit comprised of twomultipliers, 602 and 604, and two adders, 601 and 603, as shown in FIG.6, N/2×log₂N butterfly processing units are combined to implementN-point FFT.

As an example, 4-point FFT and 8-point FFT will be described below. FIG.7 is a diagram illustrating an example of the internal configuration ofthe FFT section at the time of 4-point FFT. 4-point FFT is implementedby using four (=4/2×log₂4) butterfly processing units and connecting theprocessing units as shown in FIG. 7.

FIG. 8 is a diagram illustrating an example of the internalconfiguration of the FFT section at the time of 8-point FFT. 8-point FFTis implemented by using twelve (=8/2×log₂8) butterfly processing unitsand connecting the processing units as shown in FIG. 8.

Herein, attention to a dotted portion in FIG. 8 reaches that the portionis the same as in FIG. 7. In other words, N-point FFT includes N/2^(n)(n is an integer of one or more) FFT. Using this property, butterflyprocessing units are provided in advance according to the larger numberof samples among radio communication systems using FFT, and connectedcorresponding to the number of samples of a radio communication systemin reconfiguration, thereby implementing the shared use.

Accordingly, as the information set in reconfiguration, the number ofsamples is input as control information.

Further, k_(i) in FIG. 6 represents exp (−j2πi/N) in N-point FFT, and isdetermined uniquely by the number of samples, N. Herein, i represents aninteger of 0≦i≦N/2−1, and j represents the imaginary part (j²=−1).

In addition, as another method, such a method is considered that only4-point FFT is mounted, and operated three times in 8-point FFT, inother words, processing units are prepared according to the smallernumber of samples among radio communication systems to use, and in thelarger number of samples, FFT is executed several times in time divisionto implement.

Further, it may be possible that two-point FFT (butterfly processingunit) is only mounted, and operated four times in 4-point FFT, whilebeing operated eight times in 8-point FFT, in other words, a basicconfiguration smaller than that in any radio communication system isprovided and operated a plurality of times in each radio communicationsystem. Thus, in the communication apparatus of the present invention,portions shared by FFT are not reconfigured, and the other portions arereconfigured.

Thus, according to the communication apparatus of this Embodiment, byreconfiguring processing portions varying with the number of items ofdata to perform orthogonal transform, it is possible to decrease anamount of data to reconfigure, reduce the time required for download,and switch between communication systems for a short time.

Similarly, by comparing FIG. 3 with FIG. 5, it is understood that firstcorrelator 212 and second correlator 203 are used in both figures. FIG.9 is a block diagram of a correlator in the case of QPSK as an example.In FIG. 9, input signals in_i and in_q are multiplied by spreadingsignal sequences code_i and code_q in multipliers 901, 902, 906 and 907.Multiplier 901 multiplies in_i by code_i. Multiplier 902 multiplies in_iby code_q. Multiplier 906 multiplies in_q by code_i. Multiplier 907multiplies in_q by code_q.

Adder 903 receives results of multipliers 901 and 902 to add. Adder 908receives results of multipliers 906 and 907 to subtract. Adder 904receives outputs of register 905 with an initial value of zero and ofadder 903 to add, and stores the result in register 905. Adder 909receives outputs of register 910 with an initial value of zero and ofadder 909 to add, and stores the result in register 910.

By performing a series of such operation repeatedly by a length of thespreading signal sequence, as a result of the operation, correlationvalues out_i and out_q are respectively output from adders 904 and 909.

In addition, by regarding spreading signal sequence code code_q as zero,such a configuration can be used in BPSK. In this way, even when QPSK isused in the first radio communication system, while BPSK is used in thethird radio communication system, correlators are shared by setting thetype of modulation as control information in reconfiguration.

Thus, according to the communication apparatus of this Embodiment, byreconfiguring the connection between processing units withoutreconfiguring the processing units, it is possible to decrease an amountof data to reconfigure, reduce the time required for download, andswitch between communication systems for a short time.

Further, for simplicity in descriptions, the case of QPSK and BPSK isexplained as an example, but it is possible to share processing units byproviding modifications as appropriate even when other systems are usedas a modulation system.

FIG. 10 is a diagram illustrating an internal configuration of thecompensation section of the communication apparatus of this Embodiment.Compensation section 205 in FIG. 1 supports various modulation systemssuch as QPSK and QAM. FIG. 10 illustrates a configuration ofcompensation section 205.

Input data “in” is input to switch 1001. When the data is of a knownsignal, switch 1001 is connected to the PL side, and the data is inputto channel estimation section 1002. Meanwhile, when input data “in” isnot of a known signal, switch 1001 is connected to the DATA side, andthe data is input to amplitude/phase correction section 1003.

Channel estimation section 1002 receives the type of modulation and atheoretical value of the known signal as the control information,compares the input known signal with the theoretical value to determinean amount of phase rotation and a degree of amplitude distortion basedon the control information, and thereby derives a phase correctionamount and amplitude correction amount to output to amplitude/phasecorrection section 1003.

Amplitude/phase correction section 1003 corrects the amplitude and phaseof the input data using the input amplitude correction amount and phasecorrection amount to output to decision section 1004. Decision section1004 receives the type of modulation as the control information, readsout a table value from the input data using table 1005 at the time ofQAM, and calculates output data “out”. At the time of QPSK, the section1004 outputs the data without any processing. In addition,amplitude/phase correction section 1003 may be provided with equalizingfunction and/or RAKE reception function.

As described above, it is possible to share compensation section 205 bysetting the type of modulation and theoretical value as the controlinformation in reconfiguration.

In addition, at the time of BPSK modulation, it is not necessary toperform phase correction in particular, and only amplitude correctionmay be made when necessary.

Decoding processing will be described below. FIG. 11 is a diagramillustrating an internal configuration of the FEC section of thecommunication apparatus of this Embodiment.

FEC section 206 performs error correction on reception data coded invarious manners such as convolutional code and Turbo code. FIG. 11illustrates the configuration of FEC section 206. Input data “in” isconnected to switch 1101, and switch 1101 is connected to convolutionalprocessing section 1102 at the time of convolutional code, while beingconnected to Turbo processing section 1103 at the time of Turbo code.Data storage section 1105 is connected to switch 1104, and switch 1104is connected to convolutional processing section 1102 at the time ofconvolutional code, while being connected to Turbo processing section1103 at the time of turbo code.

Convolutional processing section 1102 and Turbo processing section 1103receive control information such as a generator polynomial, constraintlength, data length and request flag, determine whether to operate fromthe request flag, and when determining to operate, start errorcorrecting processing of the input data based on the input controlinformation.

According to circumstances, intermediate data such as, for example, pathmetric and path history is input/output to/from data storage section1105 during the operation. Meanwhile, when the operation is not carriedout, unnecessary current consumption is interrupted by shutting down theclock and power supply.

Switch 1106 is connected at its two inputs to an output of convolutionalprocessing section 1102 and an output of Turbo processing section 1103,connected to convolutional processing section 1102 at the time ofconvolutional code, while being connected to Turbo processing section1103 at the time of Turbo code, and outputs error corrected data asoutput data “out”.

By this means, FEC section 206 can be shared by setting inreconfiguration the setting of switches 1101, 1104 and 1106 asconnection information, and information such as a generator polynomial,constraint length, data length and request flag as control information.

The operation of ARQ processing section 204 will be described below. ARQprocessing section 204 is used in the first radio communication systemand third radio communication system, and receives an output of secondcorrelator 203 to store in second storage section 241. The stored dataof a single frame is output to compensation section 205 in the firstradio communication system, subjected to amplitude/phase correction incompensation section 205, and output to FEC section 206.

The data is directly output to FEC section 206 in the third radiocommunication system. FEC section 206 performs error correctingprocessing on the data, and outputs error corrected data to bitoperation section 207. Bit calculation section 207 performs errordetecting check by CRC, and outputs the result to FEC section 206.

When an error still remains, FEC section 206 performs error correctionagain, and outputs the error corrected data to bit operation section 207again. After repeating a series of such processing a predeterminednumber of times, when determining that the error is not corrected, FECsection 206 outputs a retransmission request. Upon receiving aretransmission request signal from FEC section 206, second storagesection 241 keeps the stored data, and when completing the storage ofnext-frame data, outputs the stored data of a few frames to compensationsection 205 or FEC section 206.

Meanwhile, when FEC section 206 determines that errors are allcorrected, the section 206 does not output a retransmission request. Inthis case, second storage section 241 does not keep the stored data.

As an example, FIG. 12 illustrates a flow of data when retransmission isrequested, while FIG. 13 illustrates a flow of data when retransmissionis not requested. In this example, the number of maximum repetitions istwo. FIG. 12 is a flow diagram illustrating an example of the operationwhen retransmission is requested in the communication apparatus of thisEmbodiment. FIG. 13 is a flow diagram illustrating an example of theoperation when retransmission is not requested in the communicationapparatus of this Embodiment.

In FIG. 12, second correlator 203 outputs Nth frame data from time T0,and starts storing the Nth frame data in second storage section 241 fromtime T1. Storage section 241 outputs the stored Nth frame data to FECsection 206 at time T2. FEC section 206 executes error correctingprocessing.

FEC section 206 outputs error corrected data to bit operation section207 at time T3. Bit operation section 207 executes error detection byCRC operation, and reports an error detection result to FEC section 206at time T4.

When FEC section 206 determines that an error exists from the inputerror detection result, the section 206 executes the error correctingprocessing again, and outputs error corrected data to bit operationsection 207 again at time T5. Bit operation section 207 executes errordetection again by CRC operation, and reports an error detection resultto FEC section 206 at time T6.

When FEC section 206 determines that an error exists from the inputerror detection result, since the error is not corrected even afterexecuting the error correcting processing twice that is thepredetermined number of times, the section 206 outputs a retransmissionrequest.

Meanwhile, second correlator 203 outputs N+1th frame data from time T7,and second storage section 241 starts storing the N+1th frame data fromtime T8. Since retransmission is requested, storage section 241 storesthe data in another location while keeping the previously stored Nthframe.

Second storage section 241 outputs the Nth frame data and N+1th framedata to FEC section 206 at time T9. FEC section 206 executes the errorcorrecting processing, and outputs error correction processed data tobit operation section 207 at time T10. Bit operation section 207executes the error detection by CRC operation, and reports an errordetection result to FEC section 206 at time T11.

When FEC section 206 determines that an error does not exist from theinput error detection result, the section 206 does not requestretransmission. Second correlator 203 outputs the N+2th frame data attime T12, and second storage section 241 starts storing the N+2th framedata from time T13. Since retransmission is not requested, the section241 overwrites previously stored data, i.e. the Nth frame data in thisexample.

In FIG. 13, time T0′ to time T6′ is the same as in the example in FIG.12. When FEC section 206 determines that an error does not exist fromthe input error detection result at time T6′, the section 206 does notrequest retransmission. Meanwhile, second correlator 203 outputs the N+1frame data from time T7′, and second storage section 241 starts storingthe N+1 frame data from time T8′, and overwrites the previously storeddata, i.e. the Nth frame data in this example because retransmission isnot requested. The subsequent flow is the same as in FIG. 12.

In addition, for the sake of convenience, it is described in thisEmbodiment that FEC section 206 outputs a retransmission request, butthe present invention is not limited to the foregoing. CPU 105 maydetermine, for example, from a CRC result in bit operation section 207,or bit operation section 207 may determine.

Further, ARQ processing section 204 can be shared by setting whether ARQprocessing section 204 receives stored data from second correlator 203or FEC section 206 and outputs the data to compensation section 205 orFEC section 206, as connection information in reconfiguration.

Thus, according to the communication apparatus of this Embodiment, byreconfiguring only a portion of processing different between differenterror control systems, it is possible to decrease an amount of data toreconfigure, reduce the time required for download, and switch betweencommunication systems for a short time.

The operation of bit operation section 207 will be described below. Bitoperation section 207 is always used. It is assumed herein that thefirst and third radio communication systems use bit operation section207 for CRC operation, and that the second radio communication systemuses bit operation section 207 for descrambling processing. FIGS. 14,15, 16 and 17 are block diagrams common to a CRC processing unit and adescramble processor. As viewed in either figure, the right siderepresents a higher-degree side, while the left side represents thelowest-degree side, and there are shown registers 1403-1 to 1403-k-1 toshift up from the lower-degree side to the higher-degree side.

In FIG. 14, input data “in” is connected to switch 1406, and switch 1406outputs the data to either the CONV side or the CRC/DES side. An outputof the CONV side of switch 1406 is connected to switch 1404-1 and oneinput of adder 1402-1, the other input of adder 1402-1 is connected toan output of switch 1401-1, and an output of adder 1402-1 is input toregister 1403-1.

An output of register 1403-1 is connected to switch 1404-2 and one inputof adder 1402-2, the other input of adder 1402-2 is connected to anoutput of switch 1401-2, and an output of adder 1402-2 is input toregister 1403-2. Similar connection is performed repeatedly untilregister 1403-k-1, and an output of register 1403-k-1 is connected toswitch 1404-k, adder 1402-k and the CRC side that is one of three inputsof switch 1407. The other input of adder 1402-k is connected to theCRC/DES side of switch 1406. An output of adder 1402-k is connected tothe CRC side that is one of two inputs of switch 1408-2. Outputs ofswitches 1404-1 to 1404-k are all input to adder 1405, an output ofadder 1405 is connected to the DES side that is the other input ofswitch 1408, adder 1409, and the CONV side that is one of remaining twoinputs of switch 1407.

An output of switch 1408 is connected to inputs of switches 1401-1 to1401-k-1. The other input of adder 1409 is connected to the outputCRC/DES side of switch 1406, and an output of adder 1409 is connected tothe DES side that is the remaining one input of switch 1407. Output data“out” is obtained from an output of switch 1407.

The case of CRC operation will be described below with reference to FIG.15. FIG. 15 shows an example where a generator polynomial isX^(k−1)+X+1.

Switches 1404-1 to 1404-k are all OFF. Among switches 1401-1 to1401-k-1, any switch corresponding to a degree with a coefficient of “1”of the generator polynomial is ON, and the other switches are OFF.

In the case of this example, switches 1401-1 and 1401-2 are only ON.Switch 1408 is made to the CRC side, while switch 1406 is made to theCRC/DES side to input input data “in”. Meanwhile, switch 1407 is made tothe CRC side to output output data “out”.

The case of descrambling processing will be described below withreference to FIG. 16. FIG. 16 shows an example where a generatorpolynomial is X^(k−1)+X²+1.

Among switches 1401-1 to 1401-k-1, switch 1401-1 is only ON, while theother switches are OFF. Among switches 1404-2 to 1404-k, any switchcorresponding to a degree with a coefficient of “1” of the generatorpolynomial is ON, and the other switches are OFF.

In the case of this example, switches 1404-3 and 1404-k are only ON. Inaddition, switch 1404-1 is OFF. Switch 1408 is made to the DES side,while switch 1406 is made to the CRC/DES side to input input data “in”.Meanwhile, switch 1407 is made to the DES side to output output data“out”.

The connection examples of bit operation section 207 are also used as aCRC encoder or scrambler on the coding side.

Further, bit operation section 207 is used as a convolutional encoder onthe coding side. For example, FIG. 17 illustrates the case ofconvolutional code where a generator polynomial is X^(k−1)+X+1.

In other words, switches 1401-1 to 1401-k-1 are all OFF. Among switches1404-1 to 1404-k, any switch corresponding to a degree with acoefficient of “1” of the generator polynomial is ON, and the otherswitches are OFF.

In the case of this example, switches 1404-1, 1404-2 and 1404-k are onlyON. Switch 1408 is not concerned. Switch 1406 is made to the CONV sideto input input data “in”. Meanwhile, switch 1407 is made to the CONVside to output output data “out”. For simplicity, the descriptionsexplain the case of coding rate of 1/1. In the case of 1/n (n is aninteger of two or more), by providing n series of switches 1404-1 to1404-k and adder 1405 in parallel, it is possible to generate n items ofoutput data in response to a single item of input data “in” at a time.

As described above, bit operation section 207 can be shared by settingthe setting of switches 1401-1 to 1401-k-1, 1404-1 to 1404-k, and 1406to 1408 as connection information in reconfiguration.

Thus, according to the communication apparatus of this Embodiment, sincespecializing in mobile communications limits required processing,providing a required minimum reconfigurable device decreases redundantflexibility such as FPGA and PLC, and further setting the connectioninformation and control information allows more flexible response thancustom ASIC. Therefore, the need is eliminated for providing all thecircuits for each radio communication system to support, and the circuitscale can be reduced. Further, only the connection information andcontrol information is set as programming data, and it is therebypossible to reduce the download time.

In this way, as compared with conventional software radio apparatuses,the communication apparatus of this Embodiment is capable of downloadingprogramming data of a large-scale radio communication system at highspeed, and of performing handover between radio communication systemsfor a short time. Further, by this means, the need is eliminated forproviding a dedicate channel to perform high-speed download and/oraccommodating a large number of users in a wideband high-transmissionrate radio communication system, and it is thus possible to avoiddecreases in user capacity of the entire system.

This Embodiment describes about decoding section 133 that is generallypredominant in circuit scale among the baseband signal processing. Withrespect to coding section 134, as shown in the example of convolutionaloperation, it is possible to implement by expanding bit operationsection 207 as appropriate.

In addition, this Embodiment describes reconfigurable device 131 appliedto the baseband signal processing in the communication apparatus, butthe present invention is not limited thereto. The radio section, anapplication section (not shown) connected to CPU 105 or CPU 105 itselfmay be a reconfiguration device.

Further, this Embodiment describes the case that the communicationapparatus downloads programming data of a radio communicating system ofa handover destination to acquire, but the present invention is notlimited thereto. Using interface 107 of the communication apparatus inFIG. 1 allows concurrent use of a storage medium such as an SD card,flash card, memory stick and disc, or allows concurrent use of downloadby wired connection using 100BASE-TA, 10BASE-T, USB, IEEE1394 or opticalfiber (FTTH).

For example, via an ADSL modem and USB, it may be possible to select awireless service provider on the internet, download programming data ofa communication system of the selected wireless service provider, andreconfigure the communication apparatus to the communication system of adesired wireless service provider.

Further, with respect to download, it may be possible to performdownload between the communication apparatus and access point in an areasuch as a hot spot in a hotel, airport or station, substituting generalspecific power-saving wireless communications such as wireless LANtypified by IEEE802.11a/b/g, Bluetooth, and Ultra Wideband for wiredconnection typified by USB as described above, and further, it may bepossible to perform download using optical communications such as IrDA.

Moreover, the aforementioned Embodiment describes the operation on thereception side, and the operation on the transmission side is performedin the same way.

Embodiment 2

FIG. 18 is a block diagram illustrating a configuration of acommunication apparatus according to Embodiment 2 of the presentinvention. Communication apparatus 300 in FIG. 18 has signal processingcard section 301 detachable to the outside, thereby enables areconfigurable digital signal processing portion to be detachable, andin this respect, is different from the communication apparatus in FIG.1.

Signal processing card section 301 is mainly comprised of digital signalprocessing section 103, radio-section communication section 302, CPUcommunication section 303, and identification information section 304,and further provided with display 108 connected to general bus 104.

Digital signal processing section 103 transmits/receives an input/outputsignal to/from radio section 102 via radio-section communication section302. Further, the section 103 transmits/receives an input/output signalto/from CPU 105 via CPU communication section 303. Identificationinformation section 304 stores version information of signal processingcard section 301, and CPU 105 gains access to identification informationsection 304 via CPU communication section 303.

CPU 105 reads identification information for identifying a version ofthe signal processing card from identification information section 304,and referring to storage section 106, recognizes the version of theconnected signal processing card 301.

Storage section 106 stores correspondence relationship between theidentification information and the version of signal processing card301. FIG. 19 is a diagram illustrating an example of details stored inthe storage device of the communication apparatus of this Embodiment. InFIG. 19, version 1 supports radio communication system 1, version 2supports radio communication system 1 and radio communication system 2,and version 3 supports radio communication systems 1, 2 and 3.

Referring to the correspondence relationship in FIG. 19, CPU 105understands a type of radio communication system to which digital signalprocessing section 103 is reconfigurable, from the recognized version.Accordingly, CPU 105 selects a currently optimal radio communicationsystem from among reconfigurable radio communication systems, andenables digital signal processing section 103 to be reconfigured.Further, CPU 105 stores the selected radio communication system inidentification information section 304.

Meanwhile, identification information section 304 has a storage areatherein as shown in FIG. 20, and stores the version of signal processingcard 301 and the selected radio communication system. FIG. 20 is a blockdiagram illustrating a configuration of the storage section of thecommunication apparatus of this Embodiment. Identification informationsection 304 stores the version of signal processing card 301 and theselected radio communication system in storage area 305.

Radio-section communication section 302 is an interface that connectsdigital signal processing section 103 and radio section 102. FIG. 21 isa block diagram illustrating a configuration of the radio-sectioncommunication section of the communication apparatus of this Embodiment.As shown in FIG. 21, radio-section communication section 302 receivesdata from radio section 102 using input clock and reception serial data.Radio-section communication section 302 transforms the input serial datainto parallel data in serial/parallel transformer (S/P) 306, and outputsa reception control signal and reception data to digital signalprocessing section 103.

Further, in the direction opposite thereto, radio-section communicationsection 302 receives transmission data from digital signal processingsection 103 using a transmission data, transforms the data into serialdata in parallel/serial transformer (P/S) 307, and outputs thetransmission data to radio section 102 as transmission serial data.

In addition, in the similar constitution as in radio-sectioncommunication section 302, CPU communication section 303 alsoreceives/outputs data from/to CPU 105. CPU communication section 303outputs data input from CPU 105 to digital signal processing section 103or identification information section 304, and further outputs datainput from digital signal processing section 103 or identificationinformation section 304 to CPU 105.

Herein, descriptions are given of identification information section 304explicitly separated from digital signal processing section 103, butaccording to configurations, identification information section 304provided inside digital signal processing section 103 allowsimplementation in the same way.

Further, when signal processing card section 301 has extra connectionpins to connect to the outside, radio-section communication section 302or CPU communication section 303 may be implemented by bus connection,instead of serial connection.

Thus, according to the communication apparatus of this Embodiment, byenabling a portion that reconfigures only a portion different among aplurality of radio communication systems to be detachable, it ispossible to expand to a card into which more reconfigurable elements areintegrated, and it is thereby possible to cause the communicationapparatus to support a larger-scale radio communication system.

Embodiment 3

FIG. 22 is a block diagram illustrating a configuration of acommunication apparatus according to Embodiment 3 of the presentinvention. Communication apparatus 400 in FIG. 22 hasattaching/detaching detection section 401, display section 402, powersource supply section 403, and battery 619, enables a portion thatreconfigures only a portion different among a plurality of radiocommunication systems to be detachable, halts power supply to a radiotransmission portion when the portion to reconfigure is detached, whilesupplying power to the radio transmission portion and the portion toreconfigure when the portion to reconfigure is attached, and in thisrespect, differs from the communication apparatus in FIG. 18.

Attaching/detaching detection section 401 detects connection betweensignal processing card 301 and communication apparatus 400, and when thecard 301 is not connected, inputs a detaching detection signal to CPU105 to notify that signal processing card 301 does not exist incommunication apparatus 400.

When it is notified that signal processing card section 301 does notexist in communication apparatus 400, CPU 105 displays a warning suchthat “no communication card exists” on display section 402 to inform auser, and outputs an instruction for turning off the power to supply toradio section 102 and signal processing card section 301, using a powersource ON/OFF signal connected to power source supply section 403.

According to the power source ON/OFF signal output from CPU 105, powersource supply section 403 turns off the power supply to radio section102 and signal processing card section 301 from battery 619.

By the aforementioned operation, it is possible to prevent unnecessarypower consumption on the peripheries of radio section 102 and signalprocessing card section 301, and to control radio section 102 not totransmit an unnecessary radio signal. Further, at this point,communication apparatus 400 executes only the functions as anapplication terminal such as display, replay and edition of stored datasuch as image, music and mail, using display section 402, interfacesection 107 and storage section 106.

When CPU 105 detects that signal processing card 301 is connected tocommunication apparatus 400 via attaching/detaching detection section401, CPU 105 displays information such that “the communication card isconfirmed” or “wireless communications are available” on display section402 to inform a user, and outputs an instruction for supplying the powerto radio section 102 and signal processing card section 301, using apower source ON/OFF signal connected to power source supply section 403.

According to the power source ON/OFF signal output from CPU 105, powersource supply section 403 starts supplying the power to radio section102 and signal processing card section 301 from battery 619.

Attaching/detaching detection section 401 is actualized using delayelements and logic gates as shown in FIG. 23. FIG. 23 is a diagramillustrating a configuration of the attaching/detaching detectionsection of the communication apparatus of this Embodiment.

Using a differential circuit as shown in FIG. 23, and further using aconnection signal which is connected to GND in signal processing cardsection 301 such that the signal is pulled up to be “1” when signalprocessing card section 301 is removed, while being “0” when the section301 is connected, a low pulse is output to attaching/detaching detectionsignal 1 when the connection signal is switched to “0” from “1” as shownin timing, i.e. when the removed signal processing card section 301 isconnected.

Meanwhile, when the connection signal is switched to “1” from “0”, i.e.when the connected signal processing card section 301 is removed, a lowpulse is output to attaching/detaching detection signal 2. Theseattaching/detaching detection signals are input to CPU 105, whereby CPU105 is capable of detecting attaching/detaching of signal processingcard section 301.

As shown in FIG. 24, power source supply section 403 is provided thereinwith switch 4031, and turns ON or OFF switch 4031 according to a powersource ON/OFF signal from CPU 105. When switch 4031 is ON, the section403 supplies the power from battery 619 to radio section 102 and signalprocessing card section 301. On the other hand, when switch 4031 is OFF,the section 403 interrupts supply of the power.

Thus, according to the communication apparatus of this Embodiment, byenabling a portion that reconfigures only a portion different among aplurality of radio communication systems to be detachable, and haltingpower supply to a radio transmission portion when the portion toreconfigure is detached, while supplying the power to the radiotransmission portion and the portion to reconfigure when the portion toreconfigure is attached, it is possible to prevent unnecessary radiosignals from being transmitted, perform functions only as an applicationterminal, and reduce power consumption.

Further, when detaching is detected, by displaying a status ofdetaching, it is possible to alert a user.

Embodiment 4

FIG. 25 is a block diagram illustrating a configuration of acommunication apparatus according to Embodiment 4 of the presentinvention. Communication apparatus 500 in FIG. 25 is comprised of radiocommunication section 501 and application section 502, thus separatedinto radio communication section 501 and application section 502, and inthis respect, differs from the communication apparatus in FIG. 22.

Radio communication apparatus 501 and application section 502 areprovided with respective CPUs, and the CPU of radio communicationsection 501 is referred to as call control CPU 605, while the CPU ofapplication section 502 is referred to as CPU 615. Then, radiocommunication section 501 is provided with application communicationsection 608, while application section 502 is provided with call controlcommunication section 618, thereby implementing communications betweentwo CPUs. More specifically, it is possible to implement in the same wayas in the configuration of radio communication apparatus 302 in FIG. 21as described in Embodiment 2.

Attaching/detaching detection section 401 and power source supplysection 403 as described in Embodiment 3 are provided inside radiocommunication section 501, and attaching/detaching detection section 505and power source supply section 504 are newly provided also insideapplication section 502.

When application CPU 615 detects that radio communication section 501does not exist in communication apparatus 500 via attaching/detachingdetection section 505, the CPU 615 displays a warning such that “thewireless communication function is not available” to inform a user, andhalts communications with radio communication section 501.

Further, using a power source ON/OFF signal connected to power sourcesupply section 504, application CPU 615 outputs an instruction forturning off the power to supply to radio communication section 501. Bythis means, at the time radio communication section 501 is opened, evenwhen an output of power source supply section 504 becomes shortedaccidentally with GND or a signal of an external apparatus, it ispossible to prevent unnecessary power consumption and risk such asignition and failure. At this point, application section 502 incommunication apparatus 500 executes only the functions as anapplication terminal such as display, replay and edition of stored datasuch as image, music and mail, using display section 402, interfacesection 617 and storage section 616.

On the other hand, when application CPU 615 detects that radiocommunication section 501 is connected to communication apparatus 500via attaching/detaching detection section 505, the CPU 615 displaysinformation such that “wireless communications are available” on displaysection 402 to inform a user, and starts supplying the power to radiocommunication section 501, using a power source ON/OFF signal connectedto power source supply section 504.

Battery 619 supplies the power to radio communication section 501 andapplication section 502, and is charged when the power is supplied froman external power source such as an external device.

In addition, it may be possible that connector 503 is provided betweenradio communication section 501 and application section 502, and that asignal between application communication section 608 and call controlcommunication section 618 is connected or separated using connector 503.Similarly, the power to supply from battery 619 to radio communicationsection 501 may be connected or separated via connector 503.

Thus, in the communication apparatus, radio communication section 501and application section 502 are separated, first housing 801 isinstalled with radio communication section 501, while second housing 802is installed with application section 502 as shown in FIG. 26, housings801 and 802 are connected with connector 503, and it is thereby possibleto connect or separate first housing 801 and second housing 802.

In this way, for example, as shown in FIG. 27, radio communicationsection 501 in first housing 801 is connected to, for example, apersonal computer, PDA or external device 700 of a train, bus or car,and is capable of functioning as a modem card of external device 700. Inthis case, external device 700 supplies the power to radio communicationsection 501 via connector 503.

Meanwhile, for example, as shown in FIG. 28, application section 502 insecond housing 802 is connected to, for example, a personal computer,PDA or external device 700 of a train, bus or car, external device 700reads and/or writes application data in storage section 616, and thus,the data can be input and output. Further, a user is capable of removingonly second housing 802 to use as an application terminal. When externaldevice 700 is connected to application section 502, external device 700is also capable of charging battery 619, while supplying the power toapplication section 502, via connector 503.

Thus, according to the communication apparatus of this Embodiment, auser is capable of expanding to a card into which more reconfigurableelements are integrated, and it is thereby possible to cause thecommunication apparatus to support a larger-scale radio communicationsystem. Further, first housing 801 and second housing 802 can beseparated, and therefore, used in another way such as an applicationterminal and a modem card of an external device, other than a radiocommunication terminal, and it is possible to carry only either of thehousings according to the application.

Further, by standardizing the connector, for example, in USB orIEEE1394, it is possible to purchase only application section 502, forexample, installed with latest display section 402 to replace, therebyenabling less expensive replacement than the conventional case whereradio communication section 501 is present. Meanwhile, it is possible topurchase only radio communication section 501 inexpensively. Further, itis possible to select different manufacturers for radio communicationsection 501 and application section 502 corresponding to userpreference.

Furthermore, by connecting connector 503 in a specific power-savingradio communication system such as, for example, Bluetooth and UWB(Ultra Wide Band), it is possible to separate first housing 801 andsecond housing 802 with the communication function kept. For example,such a usage method is made possible that relatively large housing 801is put into a bag of a user, while the user carries relatively smallsecond housing 802 thereon, and thus, the need is eliminated that theuser always holds the two housings by hand unlike the conventional case.There arises another advantage for reducing in size and weight aterminal to wear.

In addition, the present invention is not limited to aforementionedEmbodiments, and is capable of being carried into practice with variousmodifications thereof. For example, the above-mentioned Embodimentsdescribe the case of implementation as a communication apparatus, butthe present invention is not limited to such a case. It may be possibleto implement the communication apparatus reconfiguration method assoftware.

For example, it may be possible that a program for executing thecommunication apparatus reconfiguration method is stored in ROM (Readonly Memory) in advance, and is operated by a CPU (Central ProcessorUnit).

Further, it may be possible that a program for executing thecommunication apparatus reconfiguration method is stored in a computerreadable storage medium, the program stored in the storage medium isstored in RAM (Random Access Memory) of a computer, and the computer isoperated according to the program.

Furthermore, while in the above descriptions orthogonal transform isperformed using FFT means, the means of orthogonal transform is notlimited to Fourier transform, and any means is available as long asorthogonal transform is obtained. For example, it may be possible to usediscrete cosine transform or the like.

As is apparent from the foregoing, according to the communicationapparatus and communication apparatus reconfiguration method of thepresent invention, in a communication apparatus which downloadsprogramming data of a radio communication system of a handoverdestination, and reconfigures a reconfigurable device using thedownloaded data, the communication apparatus is originally provided withprocessing units that can be shared by a plurality of radiocommunication systems, downloads as the programming data only connectioninformation of connection between the internal processing units,connection information of connection inside the processing units andcontrol information, and is thereby capable of reducing the circuitscale and an amount of programming data and shortening the downloadtime.

As a result, the need is eliminated for providing a download dedicatedchannel to perform high-speed download and accommodating a large numberof users in a wideband high-transmission rate radio communicationsystem, and it is thus possible to avoid decreases in user capacity ofthe entire system. It is further possible to reduce the circuit scale.

This application is based on the Japanese Patent Application No.2002-294031 filed on Oct. 7, 2002, entire content of which is expresslyincorporated by reference herein.

INDUSTRIAL APPLICABILITY

The present invention is suitable for use in communication apparatuses.

1. A communication apparatus comprising: a radio section that receives aradio signal to convert into a baseband signal; a baseband signalprocessor that executes processing that is common among a plurality ofradio communication systems and processing that is different among theplurality of radio communication systems on the baseband signal; and areconfiguring section that reconfigures only a portion in the basebandsignal processor that executes the processing that is different amongthe plurality of radio communication systems, based on programming dataof a new radio communication system upon switching of radiocommunication systems, and halts at least one of a clock and a powersupply in an unused portion in the baseband signal processor.
 2. Thecommunication apparatus according to claim 1, wherein the portion in thebaseband signal processor that executes the processing that is differentamong the plurality of radio communication systems comprises: asynchronization section that establishes synchronization ofcommunications, and a compensator that corrects amplitude or a phase ofthe baseband signal.
 3. The communication apparatus according to claim2, wherein: the portion in the baseband signal processor that executesthe processing that is different among the plurality of radiocommunication systems comprises an FFT section that executes orthogonaltransform on the baseband signal, and the reconfiguring sectionreconfigures a processing portion of the FFT section, the processingportion varying with the number of items of data subjected to theorthogonal transform.
 4. The communication apparatus according to claim3, wherein the synchronization section determines synchronization timingusing a baseband signal obtained by demodulating a signal mapped on asubcarrier by the orthogonal transform in the FFT section.
 5. Thecommunication apparatus according to claim 2, wherein: the portion inthe baseband signal processor that executes the processing that isdifferent among the plurality of radio communication systems comprises acorrelation section that executes correlation processing of the basebandsignal, and the reconfiguring section reconfigures a combination ofoperations in the correlation section.
 6. The communication apparatusaccording to claim 5, wherein the synchronization section determinessynchronization timing using a result of the correlation processing ofthe baseband signal in the correlation section.
 7. The communicationapparatus according to claim 1, wherein: the portion in the basebandsignal processor that executes the processing that is different amongthe plurality of radio communication systems comprises an errorcontroller which performs error correction of the baseband signal or aretransmission request when the baseband signal has an error, and thereconfiguring section reconfigures a processing portion of the errorcontroller, the processing portion different among a plurality of errorcorrection systems or error detection systems.
 8. The communicationapparatus according to claim 7, further comprising: a storage sectionthat stores a result of processing of the error controller, wherein thereconfiguring section reconfigures connection with an output destinationof content stored in the storage section.
 9. The communication apparatusaccording to claim 1, wherein the reconfiguring section acquiresinformation required for reconfiguration from the radio signal receivedin the radio section to reconfigure the portion in baseband signalprocessor that executes the processing that is different among theplurality of radio communication systems.
 10. The communicationapparatus according to claim 1, further comprising: an interface sectionthat reads out data stored in the storage section, wherein thereconfiguring section acquires information required for reconfigurationfrom the storage section via the interface section to reconfigure theportion in the baseband signal processor that executes the processingthat is different among the plurality of radio communication systems.11. The communication apparatus according to claim 1, furthercomprising: an interface section that receives information required forreconfiguration, in wired connection, wherein the reconfiguring sectionacquires the information required for reconfiguration from the storagesection via the interface section to reconfigure the portion in thebaseband signal processor that executes the processing that is differentamong the plurality of radio communication systems.
 12. Thecommunication apparatus according to claim 1, further comprising: aninterface section that receives information required forreconfiguration, in specific power-saving radio communications, whereinthe reconfiguring section acquires the information required forreconfiguration from the storage section via the interface section toreconfigure the portion in the baseband signal processor that executesthe processing that is different among the plurality of radiocommunication systems.
 13. The communication apparatus according toclaim 1, further comprising: a radio-section communication section thatrelays communications between the radio section and the baseband signalprocessor; and a CPU communication section that relays communicationsbetween the baseband signal processor and the reconfiguring section,wherein the baseband signal processor is detachable.
 14. Thecommunication apparatus according to claim 13, further comprising: anattaching/detaching detector that detects attaching/detaching of thebaseband signal processor; and a first power source supplier whichsupplies power to the radio section, and when detaching of the basebandsignal processor is detected, halts supply of the power to the radiosection.
 15. The communication apparatus according to claim 13, furthercomprising: a radio communication section that performs radiocommunications; an application section that performs display, replay andedition of data of image, music and mail; and a connector that relayscommunications between the radio communication section and theapplication section, wherein: the radio communication section and theapplication section are separable, the radio communication sectioncomprises: a radio-section communication section that relayscommunications between the radio section and the baseband signalprocessor, a CPU communication section that relays communicationsbetween the detachable baseband signal processor and the reconfiguringsection, a first CPU, and an application communication section thatrelays communications with the application section, and the applicationsection comprises: a call control communication section that relayscommunications with the radio communication section, a separationdetector that detects separation of the radio communication section, anda second CPU that halts communications to the radio communicationsection when separation of the radio communication section is detected.16. The communication apparatus according to claim 13, furthercomprising: a radio communication section that performs radiocommunications; an application section that performs display, replay andedition of data of image, music and mail; and a connector that relayscommunications between the radio communication section and theapplication section, wherein: the radio communication section and theapplication section are separable, the radio communication sectioncomprises: a radio-section communication section that relayscommunications between the radio section and the baseband signalprocessor, a CPU communication section that relays communicationsbetween the detachable baseband signal processor and the reconfiguringsection, a first CPU, an attaching/detaching detector that detectsattaching/detaching of the second baseband signal processor, a firstpower source supplier which supplies power to the radio section, andwhen detaching of the baseband signal processor is detected, haltssupply of the power to the radio section, and an applicationcommunication section that relays communications with the applicationsection, and the application section comprises: a call controlcommunication section that relays communications with the radiocommunication section, a separation detector that detects separation ofthe radio communication section, a second power source supplier whichsupplies power to the radio communication section, and when separationof the radio communication section is detected, halts supply of thepower to the radio section, and a second CPU that halts communicationsto the radio communication section when separation of the radiocommunication section is detected.
 17. A reconfiguration method of acommunication apparatus comprising: a radio section that receives aradio signal to convert into a baseband signal; a baseband signalprocessor that executes processing that is common among a plurality ofradio communication systems and processing that is different among theplurality of radio communication systems on the baseband signal; and thereconfiguration method comprising: downloading programming data of asecond radio communication system in order to perform handover forswitching to the second radio communication system during communicationin a first radio communication system; reconfiguring a portion in thebaseband signal processor that executes processing that is differentamong the plurality of radio communication systems, based on theprogramming data; and halting at least one of a clock and a power supplyin an unused portion in the baseband signal processor.